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Projeto de investigação
THE ROLE OF FIRE IN SHAPING FOREST DYNAMICS: ASSESSING ECOLOGICAL AND MANAGEMENT DETERMINANTS OF TREE RECOVERY
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Publicações
Assessing the extent and the environmental drivers of Eucalyptus globulus wildling establishment in Portugal: results from a countrywide survey
Publication . Catry, F. X.; Moreira, F.; Deus, E.; Silva, J. S.; Águas, Ana
Tasmanian blue gum (Eucalyptus globulus) has been increasingly used in forestry outside its native range, and is nowadays one of the most important pulpwood species in the world. E. globulus has great economic importance in many countries, and in Portugal it has recently become the most widespread tree species. However, there is also an increasing concern about the potential ability of eucalypts to naturally establish from seed (wildling establishment), because of negative ecological and economic impacts this could cause. The natural establishment of this fast-growing exotic species may have undesirable consequences, but little is known about its distribution, or which are the factors influencing its occurrence. In order to investigate these issues, we characterized wildling occurrence and abundance along 3111 roadside transects adjacent to eucalypt plantations distributed throughout continental Portugal. Eucalypt wildlings were found in 60 % of the sampled transects and across all natural regions, with densities ranging from 0 to 10,000 plants ha−1 (mean = 277 plants ha−1). The potential influence of environmental variables on wildling establishment from plantations was assessed using boosted regression trees. The abundance of wildlings was found to be primarily affected by precipitation and distance from the sea (used as a surrogate of thermal amplitude), although topography, frost occurrence and soil type also played a significant role. Plant density peaked at around 1500 mm of annual precipitation and it decreased with both decreasing and increasing precipitation, reaching the lowest values below 800 mm and above 2400 mm. Eucalypt wildlings were also more abundant in areas with milder temperatures, namely closer to the sea (with lower thermal amplitude) and with lower number of frost days. Finally, plant density also seemed to be favoured in areas with intermediate elevation, higher slope and with certain soil types (namely Cambisols and Podzols). Knowing the regions with higher wildling density and understanding the factors influencing plant establishment may help managers to establish and prioritize eventual control plans in regions with higher probability of recruitment.
Investigating the invasiveness of Eucalyptus globulus in Portugal: site-scale drivers, reproductive capacity and dispersal potential
Publication . Deus, Ernesto; Silva, Joaquim S.; Larcombe, Matthew J.; Catry, Filipe X.; Queirós, Luís; Santos, Patrícia dos; Matias, Hugo; Águas, Ana; Rego, Francisco C.
Plantations of Eucalyptus globulus Labill. have expanded rapidly over the last four decades across temperate parts of the globe. There has been growing concern about the potential invasiveness of this species. Portugal grows more E. globulus than any other country (by area). This study investigates poorly understood factors that may influence wilding establishment and spread from Portuguese plantations. We assessed: site-scale factors influencing the presence and abundance of E. globulus wildlings along plantation edges, as well as the size and reproductive state of these wildlings; and the dispersal distances and developmental state of wildlings away from the plantations edge. We found 1630 E. globulus wildlings in 129 survey plots (10 × 10 m) established along the edge of 67 plantations. Half of the surveyed wildlings were taller than 1.3 m. The presence and abundance of E. globulus wildlings was mainly influenced by factors such as soil cover, the age of mother-trees and their reproductive output. Around 8% of the surveyed wildlings were reproductive, including wildlings less than 1.3 m tall. The proportion of reproductive wildlings was mainly influenced by wildling size, the location relative to the plantation edge and the annual number of frost days. In 49 survey transects outside plantations we found 641 E. globulus wildlings up to a distance of 76 m. Establishment distance was associated with natural drainage lines and the dominant wind direction. We discuss the relevance of the results in terms of the potential invasiveness of E. globulus.
Unidades organizacionais
Descrição
Palavras-chave
, Agricultural sciences ,Agricultural sciences/Agriculture, forestry, and fisheries
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Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia, I.P.
Fundação para a Ciência e a Tecnologia, I.P.
Fundação para a Ciência e a Tecnologia, I.P.
Programa de financiamento
POR_NORTE
Número da atribuição
SFRH/BPD/93373/2013